JP2984290B2 - Equipment for catalytic reaction - Google Patents

Description

The present invention relates to an apparatus for conducting a catalytic reaction and to the use of an apparatus of this type.

Catalytic solid reaction beds are representative of an important field of use of the present invention, for example, in oxidation and hydrogenation reactions.

In a known embodiment of this type of reactor, the space in which the reaction takes place is filled with a particulate solid catalyst,
The shape may be, for example, spherical or pellet, around which the reactant flows.

On the one hand, in addition to a considerable pressure drop occurring in this type of reactor, on the other hand, there is no uniform temperature distribution with respect to the reactor cross section. Further disadvantageous is the fact that the yield of the required end product is not as high as possible, since there is also no uniform concentration distribution with respect to the reactor cross section.

Finally, since a considerable number of normal chemical reactions are exothermic, local heating parts (so-called hot spots) occur in the reaction bed in this case. This limits the useful life of the catalytic material and reduces its selectivity, especially the selectivity of the oxidation reaction.

To avoid the effects of local heating that occurs in this case,
That is, in order to improve the conduction of heat to the inner wall of the reactor, it is usual that a large number of catalyst-filled tubes are arranged in the reaction space, and a heat-absorbing medium flows around these tubes. However, embodiments of this type are very expensive to operate and manufacture.

Indeed, if the layers of the device are formed of a catalytic material, whether this is possible depends on whether the material can be formed as simply as required. Materials of this type can also be very expensive.

An object of the present invention is to provide a device that enables a long effective life to be obtained when a catalytic reaction is carried out by using a catalytic substance advantageously, and further allows a wider selection range of the catalytic substance to be used. It is to be. Thus, the present invention is applicable to both solid catalyst materials, such as platinum, metal oxides, or ion exchange resins, and catalyst solutions, such as aqueous solutions of platinum oxide and copper chloride, or liquid catalyst materials, such as sulfuric acid or hydrochloric acid. It is possible. With the present invention, it is also possible to use gaseous catalytic substances, for example hydrogen chloride or hydrogen fluoride.

The object of the present invention is achieved by the present invention having the features described in claim 1. The dependent claims relate to particularly advantageous embodiments of the invention.

Uniform temperature distribution, uniformity of concentration in cross section, short residence time and very little backmixing (if any)
Shows the essential advantages of the present invention. Uniform temperature uniformity and good heat transfer to the reactor walls are particularly critical factors for the longevity of the catalyst and the high yield and selectivity. This effect is particularly important for exothermic reactions because the heat generated from the exothermic reaction is more rapidly transferred from the heated location to the reactor wall. This effect also improves the operational safety (does not cause runaway).

Of considerable importance is also the fact that the uniform temperature distribution and the uniformity of the concentration with respect to the reactor cross section allow the desired reaction products to be obtained in large quantities and of high quality, while the unreacted materials are relatively free. The fact is that it stops in a small amount.

Furthermore, the essential advantages of the present invention are the properties known only in the pure mixing process itself, such as uniform temperature distribution and uniformity of concentration with respect to cross section, short residence times and very little backmixing (If any) are also used in the present invention.

The solid bed reactor to which the apparatus of the present invention is attached can be made using a significantly smaller number of tubes than other solid bed reactors of the same flow rate. If there is one apparatus of the present invention, it is possible to fully realize a solid bed reactor. That is, in this case, the cross-sectional area of the apparatus of the present invention corresponds to the cross-sectional area of the reactor housing.

It is also advantageous to arrange several devices of this type one above the other in the reactor housing. At this time, the overlapped devices are staggered by about 90 degrees with respect to the long axis of the reactor.

The so-called catalytic distillation process, ie a process consisting essentially of a combination of a catalytic reaction and a distillation or rectification process, is representative of the fields in which the invention is advantageously applied.

This type of process and its many applications are described, for example, in the February 1987 issue of Chemical Processing.
al Processing), Houston
District Editor William Peace Taddig
Stadig), “CATALYTIC DISTILLATION, Combining chemical.
reaction with product separation).

Known reaction rectification columns comprise at least one solid bed reactor and a mass transfer zone, in which products based on the reaction are separated from unreacted products and unwanted by-products. The rectification is a continuous process, so rectification occurs in addition to the catalytic reaction in the contact area, but its temperature is preferably the boiling point of the product to be obtained, and the boiling point adjusts the column pressure accordingly. Control. Details regarding the procedure for implementing this type of combination are given in the above-mentioned article.

In a known manner, a so-called coil is arranged in the contact area. These coils have a function of holding a solid catalyst, but are wound around a stainless steel mesh, and this mesh forms a layer made of glass fiber and containing corrosive catalyst particles. Is firmly held. The advantage of this embodiment is that it is possible to manufacture the tower wall with a non-corrosive material, for example carbon steel, since the tower wall does not come into contact with the contact substance.

In contrast to the static mixer arrangement arranged according to the invention, these coil bodies have considerable disadvantages. It is because there is no radial temperature and concentration uniformity across the column cross section, and there is a relatively large pressure drop due to the non-uniform flow of reactants or products resulting from the reaction in addition to by-products. That is the fact. This is not the case with the static mixer arrangement arranged according to the invention.

Replacing the known coils in the catalytic reaction zone with the structure of the present invention will achieve all of the advantages provided by the catalytic solid bed reactor described above.

The invention is described below on the basis of embodiments illustrated in the accompanying drawings.

 FIG. 1 is an example of an apparatus formed in accordance with the present invention.

 FIG. 1a is an exploded view of the example of FIG.

FIG. 1b and FIG. 1c are perspective views of the pocket-like layer, respectively.

2a and 2b are a side view and an elevation, respectively, of a variant.

 FIG. 3 is a catalytic solid bed reactor.

 FIG. 4 shows a rectification column for performing a complex process.

FIG. 5 is a perspective view of another embodiment of an apparatus formed in accordance with the present invention.

The device 41 shown in FIGS. 1 and 1a consists of pocket-like layers 42 which are arranged parallel to one another and in each case are attached to a guide element plate 44 at a side wall 43. Have been.

In this embodiment, the guide element plates are comprised of corrugated metal plates, the top and bottom of the corrugations forming the side walls of the reactant flow path 45.

Advantageously, these corrugated metal plates are formed such that the channels they form are at an angle to the longitudinal axis of the pocket 42 (see FIGS. 1b and 1c).

Next, when assembling the reactor 41 by stacking adjacent layers, the layers are stacked so that the flow paths of the adjacent pockets 42 intersect. This often results in radial cross-mixing of the reactant component streams, resembling a static mixer, especially when a plurality of devices 41 are placed on top of each other, preferably offset by about 90 degrees.

The guide element plate 44 simultaneously serves to reinforce the pockets 42, which are attached to the guide element plate by, for example, spot welding. The ridges of the guide element plate abut the side walls of the adjacent pocket without the guide element plate and thus simultaneously serve as spacing means. It should be noted that the term "waveform" also means a zigzag folded plate.

As in the embodiment, the guide element plate 44 may be constituted, for example, by a metal plate, a metal perforated plate, a plastic or woven wire mesh or a similar plate, which are, for example, indicated in the dependent claims. Have been.

According to the invention, the side walls 43 of the pockets 42 are fixed at their side edges, for example, by tacking, welding or brazing, but are permeable to the reactants, but the catalyst is It consists of substances that do not pass through. Examples of this type of material are set forth in the dependent claims herein.

The solid, liquid, or gaseous catalyst 46 is selected according to the purpose of use, but is used in the pocket 42.

It is also possible to fill the pocket-like internal space with an injectable catalytic substance. In this case, the catalyst is mixed with a plastic substrate, which is polymerized to form a mass of porous material that is permeable to the reactants.

Another possibility is to fill the internal space with an injectable catalyst,
The catalyst is then treated accordingly to form a porous ceramic or a sintered structure therefrom.

In this embodiment, the device has a circular cross section. The cross-sectional shape depends on the shape selected for the reactor housing, and may be, for example, any of a square, a rectangle, and a polygon.

In the embodiment shown in FIGS. 2a and 2b, the guide element plate of the pocket 42 'is formed from a bar-shaped part 47 and is attached to the wall 43' of the pocket, for example by spot welding. Apart from this, the first, 1a, 1b and 1c
All the above information on the embodiment of the invention shown in the figures applies.

FIG. 3 shows a catalytic solid bed reactor 6 which is housed in a cylindrical housing 7. The tube 8, the opening end of which is held by the tube sheet 9, is arranged in the housing 7.

Apparatus 10 is formed in accordance with the present invention, but is disposed overlying within tube 8 and, when formed as in the embodiment shown in FIGS. 1, 1a-1c, and 2a and 2b, is not associated with an adjacent apparatus. They are staggered at a 90 ° angle to the tube axis.

The pipe connection ports 12 and 13 are connected to the heat exchange space 11 and supply and remove a heat supply and heat removal medium, for example, a molten salt. The heat carrier flows around the tube 8.

Inlet space for reactants fed through connection sleeve 15
14 is arranged below the reaction tube 8, and an outlet space 16 for discharging products and by-products is arranged above the reaction tube 8.

In one embodiment of the catalytic reaction, the connecting sleeve 15
And a mixture of air and n-butane is passed through the tube through the inlet space 14. The temperature is, for example, from 200 to 300 ° C., in which case the reaction can be carried out at about 1 bar.

In this case, phosphorus pentoxide and vanadium pentoxide can be used as the catalyst.

This reaction is an exothermic reaction, and the generated heat is absorbed in, for example, a molten salt flowing through the reaction tube 8. Although not shown in detail, the heated molten salt exits from the outlet 13, is cooled to a required temperature, and is circulated to the heat exchange space 11 through the inlet 12.

In the case of the present example, the product obtained is maleic anhydride in gaseous form, which is supplied from the reactor 6 via the outlet 17 and sent to the further processing steps. This is because the product is not obtained in pure form, and impurities, in this case the starting n-butane and by-products in the production of maleic anhydride, such as oxygen,
This is because it is mixed with water, maleic acid, carbon monoxide and carbon dioxide.

The subsequent treatment step can be performed, for example, by a method known per se as a distillation step.

By using the apparatus formed according to the invention and enjoying its advantages, significantly less tubes are required than the known reactors mentioned at the outset. Overheating is prevented, at least to a considerable extent, by good heat transfer at the tube wall, so that carbon monoxide, carbon dioxide and water are so reduced as to reduce the selectivity and activity of the catalyst as compared to known embodiments. Is relatively small.

Embodiments of a catalytic solid bed reactor with only one tube are also possible, in which case at least one of the devices according to the invention is provided.

FIG. 4 illustrates a catalytic distillation column 20 in which a catalytic solid bed reactor 21 containing an apparatus formed in accordance with the present invention (see, for example, FIG. 1) is located. I have.

Mass transfer zones 22 and 23 are located above and below this solid bed reactor zone 21, respectively. Product mass transfer that occurs in reaction zone 21 occurs in zones 22 and 23. These areas can be made with conventional equipment, for example, perforated or bubble-shaped shelves. The liquid and gas or vapor phases can pass through these packings in countercurrent. The layers folded in multiple layers can be formed as a single layer. That is, it is possible not to have a double wall in the internal space.

Apart from the reaction taking place in the solid catalyst bed 21 between the reactants fed via the tubes 24 and 25, the reaction mixture is also distilled in this zone.

An outlet 26 for the liquid bottom product is provided at the bottom of the column. A portion of this bed product is recycled to column 20 via tube 27 after evaporation in evaporator 28 in a conventional manner.

A tube 29 for withdrawing gaseous or vaporous top products is also provided at the top of column 20 according to conventional methods. After this overhead product is liquefied in the condenser 30, a portion of it is returned from the tube 31 to the column as reflux. On the other hand, the remaining liquid is taken out of the rectification step via the tube 32.

The advantages of the solid bed area 21 formed in accordance with the present invention are the same as those of the embodiment shown in FIG.

Since the rectification column 20 is operated at the boiling point of the product resulting from the reaction, it is needless to say that there is no superheated portion. The heat resulting from the exothermic reaction is only used to evaporate the liquid phase. However, this is an important advantage from an energy point of view. This is because the required capacity of the evaporator 28 is reduced.

With the present invention, it is also possible to scale up this type of plant while having the advantages described above.

The solid bed area 21 is disposed in the middle, lower, or upper stage of the column depending on the process. The purpose of this embodiment is to obtain 3-methylbutyl ether from a mixture of saturated and unsaturated chain hydrocarbons having 4 carbon atoms.

The reactant consisting of methanol is fed to column 20 via tube 24 above zone 21. On the other hand, the reactant consisting of a mixture of saturated and unsaturated chain hydrocarbons having 4 carbon atoms is placed in the lower tube
Feed to tower 20 via 25.

The unreacted chain hydrocarbon having 4 carbon atoms is transferred to the mass transfer region 22.
Is separated countercurrently from the reaction product toward the liquid phase at
Is taken out in the form of steam at the top of the
Some is returned to tower 20 as reflux. The remaining liquid may be returned, for example, as a reactant to column 20 via column 25.

The final product, which is obtained as a liquid and consists of 3-methylbutyl ether, is taken out of the column 20 from the bottom of the column. A part is evaporated in the evaporator 28 and circulated to the tower 20. The liquid end product is withdrawn from the plant and passed through tube 33 for further processing.

The device 51 shown in FIG. 5 consists of folded layers 52, each layer being arranged parallel to one another,
In this case, it is composed of double shells 52a and 52b. The walls are composed of a material that is permeable to the reactants but impermeable to the catalytic material.

The solid, liquid, or gaseous catalyst 54, which is selected according to the purpose of use, is used in the internal space formed by the double walls 52a and 52b.

It is also possible to fill the internal space with an injectable catalytic substance. In this case, the catalyst is mixed with a plastic substrate, which is polymerized to form a mass of porous material that is permeable to the reactants.

Another possibility is to fill the internal space with an injectable catalyst,
The catalyst is then treated accordingly to form a porous ceramic or a sintered structure therefrom.

In this embodiment, the device has a circular cross section. The cross-sectional shape depends on the shape selected for the reactor housing, and may be, for example, any of a square, a rectangle, and a polygon.

Each of the layers 52 is folded, with the fold plate 55 at an angle to the long axis of the device, and the bends in adjacent layers 52 intersecting.

Continuation of the front page (56) References JP-A-63-197533 (JP, A) JP-B-48-32277 (JP, B1) British publication 1467277 (GB, A) (58) Fields investigated (Int. ⁶ , DB name) B01J 8 / 02,19 / 32

Claims (17)

(57) [Claims] An apparatus (41,51) for performing a catalytic reaction having a plurality of layers (42,52) and a fluid path (45) existing between adjacent layers, the apparatus comprising: The layer (42, 52) has a structure having a double wall (43, 52a, 52b), and the double wall defines a space into which the catalyst material (54) composed of solid particles is introduced. Leave between the walls, the walls (43, 52a, 52b) of the layers (42, 52) are permeable to the reactants but impermeable to the catalytic material, and the structure of the layers is , 51) form a fluid path (45) at an angle to the long axis, and adjacent layers (42, 52) are placed together such that the fluid paths (45) intersect. The above device, characterized in that: 2. Device (51) according to claim 1, characterized in that the entire structure of the layer (52) is constituted by double walls (52a, 52b) leaving space. 3. The double wall (43) of said layer (42) is pocket-like, and a catalytic substance is introduced into the space of this pocket,
2. The method according to claim 1, wherein each of the pockets is reinforced on at least one of the walls by a guide element plate, at the same time the guide element plate forms the wall of the fluid channel. Device (41) according to claim 1. 4. The device (4) according to claim 3, wherein the guide element plate (44) is made of a corrugated sheet.
1). 5. The device according to claim 3, wherein the guide element plate is made of a rod-shaped component (47). 6. The device (41) according to claim 3, wherein the guide element plate (44) is made of a sheet arranged perpendicular to the pocket plane. 7. The method according to claim 1, wherein the walls of the layer are made of woven or knitted filaments.
Device according to one of claims 6 to 6. 8. The apparatus according to claim 7, wherein said filament is at least partially metallic. 9. The apparatus according to claim 7, wherein said filament is made of glass or synthetic plastic material. 10. The device according to claim 1, wherein the layer walls are made of glass fiber and / or synthetic plastic fleece. 11. The layer walls (43, 52a, 52b) are made of a porous material, the pores of which are sized to be permeable to reactants but impermeable to catalytic materials. Apparatus according to one of claims 1 to 6, characterized in that: 12. The device according to claim 1, wherein the walls of the layer are made of sintered material. 13. The method of claim 1, wherein after introducing into said space, the agglomeration of said solid particles is changed, and the resulting porous material is permeable to reactants.
Item 13. The apparatus according to any one of Items 1 to 12. 14. A porous ceramic or sintered structure permeable to reactants after being introduced into said space is formed from said solid particles.
Device according to one of the paragraphs. 15. A catalytic reactor (6) or a catalytic distillation column (20).
A method for using the device according to one of claims 1 to 14. 16. A method for producing maleic anhydride using a catalytic reactor using the apparatus according to claim 1, comprising: mixing a mixture of air and n-butane vertically with a plurality of pairs. An elongated vapor permeable wall that feeds into the spaced apart pairs and forms a fluid path between the pairs, wherein the fluid paths are each within a catalytic reactor. Having a catalyst disposed between the pair of walls and directing a flowable medium for removing heat into a heat exchange relationship between the air and the mixture of n-butane to form a gaseous anhydrous mixture of the mixture. Conducting a catalytic reaction to maleic acid and removing gaseous maleic anhydride as a product. 17. A method for obtaining methyl tert-butyl ether using a catalytic distillation column using the apparatus according to claim 1, wherein methanol is purified by a method comprising a plurality of vertically extending parallel layers. Feeding the solid catalyst section in the distillation column, wherein the parallel layers define a fluid path therebetween, each layer having a pair of walls defining at least one internal space for the catalyst material;
Further, at least one of the walls is impervious to the catalytic material but permeable to methanol, and comprises a mixture of saturated and unsaturated chain hydrocarbons having 4 carbon atoms. To the solid catalyst section for catalytic reaction with methanol to produce methyl tert-butyl ether and from the rectification column methyl tert-butyl
Removing butyl ether, a process comprising methyl-tert.
-A method for obtaining butyl ether.